It makes sense that waterfalls recede upstream over time. Niagara Falls does this at a relatively quick pace. It has already moved quite a few miles since its formation.

Currently, the falls retract about 12 inches every year. This rate varies, depending on the rock strata. During the 20th century, the average rate was about three feet. We know that, at times, Niagara Falls would erode back up to five feet annually.

In about 50,000 years, Niagara Falls will make its way back to Lake Erie. When this happens, the 210′ deep waters of Lake Erie will face an over 300 foot drop. Imagine what that’s going to look like.